Richard Dawkins' sexual selection

Richard Dawkins is a fine writer with an ingenious mind. In a long article in the Independent Review of 7 Sep 2004, under the title of The Power of Animal Attraction, he sets out to explain why late Miocene ancestral humans suddenly and rapidly first became bipedal, and then brainy.

In Idle Theory, the explanation of bipedalism is that humans started using hand-held tools like stones and bags and sticks. They started using these tools because they made work easier. But one of the side effects of using hand-held tools was that it prevented forelimbs from being used as feet, and forced the adoption of a bipedal stance. Once human held stones and bags and spears, they had to stand on their hind legs. Human technological innovation resulted in human bipedalism. And if humans got brainy, it was because designing, making, and using tools required increased imagination, planning, and hand-eye coordination. And this required a bigger brain. And the more sophisticated the tools became, the bigger the brain needed to become. Human technology co-evolved with the human brain.

Much the same explanation can be used to explain bipedalism in other animals. If birds are biped, it is because their forelimbs also became specialised - as wings.

Not according to Dawkins. Starting out with peacocks and birds of paradise, he suggests that human bipedalism and braininess are the result of a sexual selection that "produces quirky, whimsical evolution that runs away in apparently arbitrary directions, feeding on itself to produce wild flights of evolutionary fancy." Walking bipedally was something that simply became fashionable.

Our ancestors, like other apes, walked about on all fours when not up trees, but reared up on their hind legs from time to time, perhaps in something like a rain dance, or to pick fruit off low branches, or to move from one squat feeding position to another, or to wade across rivers, or to show off their penises, or for any combination of reasons, just as modern apes and monkeys do. Then - this is the crucial additional suggestion I am adding - something unusual happened in one of those ape species, the one from which we are descended. A fashion for walking bipedally arose, and it arose as suddenly and capriciously as fashions do. It was a gimmick."
(Richard Dawkins. Independent Review. 7 Sep 2004)

Anyway, fashion-conscious females started mating with males who could walk the walk. And their children inherited this skill in walking in the bipedal fashion. And their daughters inherited their mother's taste for swaggering males. Pretty soon our human ancestors were all walking around in the new fashion.

And what about the brain? Nothing particularly attractive about a big head. But it's what's inside it that matters.

A female who seeks a penetrating and thorough reading of the quality of a male's genes would do well to concentrate on his brain. She can't literally look at the brain, so she looks at its works. And following the theory that males should make it easy by advertising their quality, males will not hide their mental light under a bony bushel, but bring it out into the open. They will dance, sing, sweet-talk, tell jokes, compose music or poetry, play it or recite it, paint cave walls or Cistine chapel ceilings. (ibid)

So females were charmed not only by guys who could walk the walk, but who could talk the talk. And there you have it: bipedalism and braininess are fashion accessories. They pull chicks.

It's not an utterly implausible theory. But it is a playful theory. It is firstly playful in the way that all good theory is able to playfully toss ideas around. But it is also playful in that it unspokenly depicts our ape ancestors as living largely idle, playful lives in which there was plenty of time to perfect a fashionable swaggering walk, as well as sing, dance, tell jokes, compose and play music. Underpinning Dawkins' theory is a rosy vision^* of an ape life of leisure.

For it is idle time or leisure that underpins fashion. If fashions quickly come and go among teenagers, it is because during their school or university years they have plenty of idle time in which to pursue the latest fashions, before working life forces them into regimented suits or uniforms. And if high fashion - Versache, Armani, etc. - persists into later life, it is because there are people rich enough to continue to lead the kind of idle life that permits fashion to continue to flourish.

And in the same way the peacock's fan advertises the peacock's idleness. It says: "Look at the surfeit of jewels and rings that I've got. Look how easy my life is. With a father like me, babe, your kids are assured an easy life." These birds of paradise are rightly named, because they only flourish in tropical, energy-rich, leisured paradises like New Guinea. Introduce a couple of foxes, and they go the way of the dodo. The greater bulk of working birds the world over are obliged to wear dull uniforms of brown or black or white, largely devoid of decoration, except perhaps a small flash of colour as a badge to identify which busy office they occupy.

If all living creatures lived largely idle lives, Dawkins' theory would well explain their diversity. But birds of paradise and peacocks are the exception rather than the rule. They may well portray how life evolves in a playground. But most life, like most people, enjoys a life of work, not play.

And equally, while it's not an entirely implausible theory, it is a theory that could be used to explain anything. If it became fashionable to walk around on two legs rather than the usual four, it could just as easily have become fashionable to walk around on two hands, or hop around on one leg. Monty Python's Ministry of Silly Walks offers a host of elaborate ways of walking, any one of which could have become fashionable. And if it became fashionable to dance, tell jokes, play music, it could just as easily have become fashionable to burp or grunt. Dawkins cites an "inane" pop song from his teens.

"Everybody's talking
'Bout a new way of walking!"

If that was inane, then what the heck was this chart-topper?

"Sittin' in the la la,
Waitin' for my ya ya,
A hm ahm."
(Lee Dorsey)

Dawkins' theory is itself a wild flight of evolutionary fancy. Therein lies its charm, because theory should be wild and fanciful and playful. But it is not a theory that bears the slightest scrutiny.